Acute renal failure in cardiac surgical patients
The onset of acute renal failure following any surgical procedure has a poor prognosis due not only to the loss of renal function, but also to other major complications including sepsis, gastrointestinal bleeding, and cardiac or pulmonary complications.1–3
It is important that the clinician be able to recognize those risk factors that may be related to the development of postoperative renal failure if patient morbidity and mortality are to be minimized. In view of the lethal nature of acute renal failure, the most effective treatment is directed toward careful selection of patients and prevention.
Definition of acute renal failure
Acute renal failure results when any process causes a rapid reduction in glomerular filtration rate (GFR), often to a level that requires dialysis support. Acute loss of renal function is reflected by a progressive rise in serum creatinine and urea nitrogen concentrations. Acute renal failure may be characterized by a striking reduction in urine volume to levels < 400 ml/dl (oliguria) or occasionally to volumes < 100 ml/dl (anuria). Although acute renal failure is characteristically accompanied by low urine flow rates, nonoliguric renal failure may occasionally be seen with normal or even increased urine flow. Other common synonyms used for acute renal failure include acute tubular necrosis, vasomotor nephropathy, lower nephron nephrosis, or shock kidney.
Cause of acute renal failure
The principle causes of acute renal failure are listed in Table 1. As will be noted, a large group of clinical problems may be associated with the syndrome of . . .